A back up power supply may be used to provide power when a wired electricity supply is unavailable. For example, during power outages or while away from a building (e.g., while camping or hunting, when providing an outdoor presentation, etc.), a back up power supply may be used to power one or more devices or pieces of equipment. In another example, a portable power supply may be used to jump start a vehicle. The source of power for the back up power supply, in some examples, may include propane, gas, and/or battery.